Axle Sensor - Operation

OPERATION

The front and rear axle sensors monitor changes in the relative distance between the vehicle body and the front or rear suspension members. The sensor circuitry is energized by the Adaptive Front Lighting System (AFLS) module and both sensors provide hard wired analog (potentiometer) inputs back to the AFLS module. The AFLS module uses these sensor inputs as logic for calculating when and how much to adjust the headlamp beams as part of the automatic headlamp leveling feature.

The body of each sensor is mounted in a fixed position, while the sensor lever arm is attached to a linkage arranged between the vehicle chassis and the front or rear suspension members. Each sensor is capable of either analog or digital outputs. The output type is determined by the wiring connections to the pins in the sensor connector receptacle. The sensor circuitry is energized by the AFLS module. As the sensor lever arm is moved, it rotates an input shaft. The input shaft rotation is monitored by the sensor circuitry, which causes changes in the output signal of the sensor. The AFLS module evaluates the output signals from the sensors to determine what changes are occurring in the front and rear suspension height of the vehicle.

The hard wired circuits for the axle sensors may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the axle sensors or the electronic controls and communication that provide the features of the AFLS system. The most reliable, efficient, and accurate means to diagnose the axle sensors or the electronic controls and communication related to AFLS operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.